Singer Lorna Luft, the daughter of Judy Garland and half-sister of Liza Minnelli (above right), has been diagnosed with a brain tumor after she collapsed backstage at a concert in London, Associated Press reported.

The singer’s representative, Victoria Varela, told TheWrap’s via email that Luft, 65, collapsed backstage Friday night following the second of her four sold out shows at London’s iconic Pizza Express Jazz Club.

Luft’s husband, Colin Freeman, had been concerned that she was forgetting lyrics and a monologue during her performance. She was rushed to London’s Chelsea and Westminster Hospital, where she was given an initial diagnosis of a brain tumor and is undergoing additional tests, Varela said.